Nodes and methods for handling paging

ABSTRACT

Embodiments herein relate generally to a Control plane, CP, node, a method performed by the CP node, a Radio Access Network, RAN, node and a method performed by the RAN node. More particularly the embodiments herein relate to handling paging.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Ser. No. 16/753,717, having asection 371(c) date of Apr. 3, 2020 (status pending), which is the 35U.S.C. § 371 National Stage of International Patent Application No.PCT/EP2018/077198, filed Oct. 5, 2018, which claims priority to U.S.provisional application no. 62/568,833, filed on Oct. 6, 2017. The aboveidentified applications are incorporated by this reference.

TECHNICAL FIELD

Embodiments herein relate generally to a Control plane (CP) node, amethod performed by the CP node, a Radio Access Network (RAN) node and amethod performed by the RAN node. More particularly the embodimentsherein relate to handling paging.

BACKGROUND

According to the current 3GPP TS 23.501 V1.4.0 (2017-09), the 5G Systemarchitecture is defined to support data connectivity and servicesenabling deployments to use techniques such as e.g. Network FunctionVirtualization (NFV) and Software Defined Networking (SDN). The 5GSystem architecture shall leverage service-based interactions betweenControl Plane (CP) Network Functions where identified. One key featureof 5G is to separate the User Plane (UP) functions from the ControlPlane (CP) functions, allowing independent scalability, evolution andflexible deployments e.g. centralized location or distributed (remote)location.

FIG. 1 and FIG. 2 illustrate examples of the architecture for a 5Gsystem. The 5G architecture is service-based and comprises networkfunctions which interact with each other. FIG. 1 illustrates anon-roaming 5G System Architecture and FIG. 2 illustrates a Roaming 5GSystem architecture-Home routed scenario. The interfaces or referencepoints between the network functions in FIGS. 1 and 2 may be referred toas service-based interfaces.

The example architectures in FIGS. 1 and 2 comprise at least some of thefollowing entities: Authentication Server Function (AUSF); Access andMobility Management Function (AMF); Data Network (DN), e.g. operatorservices, Internet access or 3rd party services; Unstructured DataStorage Function (UDSF); Network Exposure Function (NEF); NF RepositoryFunction (NRF); Network Slice Selection Function (NSSF); Policy Controlfunction (PCF); Session Management Function (SMF); Unified DataManagement (UDM); Unified Data Repository (UDR); User plane Function(UPF); Application Function (AF); User Equipment (UE); (Radio) AccessNetwork ((R)AN); 5G-Equipment Identity Register (5G-EIR).

The example 5G system architectures in FIGS. 1 and 2 comprise at leastone of the following service-based interfaces: Namf: Service-basedinterface exhibited by AMF; Nsmf: Service-based interface exhibited bySMF; Nnef: Service-based interface exhibited by NEF; Npcf: Service-basedinterface exhibited by PCF; Nudm: Service-based interface exhibited byUDM; Naf: Service-based interface exhibited by AF; Nnrf: Service-basedinterface exhibited by NRF; Nnssf: Service-based interface exhibited byNSSF; Nausf: Service-based interface exhibited by AUSF; Nudr:Service-based interface exhibited by UDR; Nudsf: Service-based interfaceexhibited by UDSF; N5g-eir: Service-based interface exhibited by 5G-EIR.

The example 5G system architectures in FIGS. 1 and 2 comprise at leastone of the following reference points: N1: Reference point between theUE and the AMF; N2: Reference point between the (R)AN and the AMF; N3:Reference point between the (R)AN and the UPF; N4: Reference pointbetween the SMF and the UPF; N6: Reference point between the UPF and aData Network; N9: Reference point between two UPFs; N5: Reference pointbetween the PCF and an AF; N7: Reference point between the SMF and thePCF; N24: Reference point between the PCF in the visited network and thePCF in the home network; N8: Reference point between the UDM and theAMF; N10: Reference point between the UDM and the SMF; N11: Referencepoint between the AMF and the SMF; N12: Reference point between AMF andAUSF; N13: Reference point between the UDM and Authentication Serverfunction the AUSF; N14: Reference point between two AMFs; N15: Referencepoint between the PCF and the AMF in case of non-roaming scenario, PCFin the visited network and AMF in case of roaming scenario; N16:Reference point between two SMFs, (in roaming case between SMF in thevisited network and the SMF in the home network); N17: Reference pointbetween AMF and 5G-EIR; N18: Reference point between any NF and UDSF;N22: Reference point between AMF and NSSF; N27: Reference point betweenNRF in the visited network and the NRF in the home network.

The current 3GPP TS 23.501 V1.4.0 (2017-09) has introduced the RadioResource Control (RRC) inactive state. 5GC shall provide the RAN withRRC inactive assistance information.

There are two Connection Management (CM) states which are used toreflect the NAS signalling connectivity of the UE with the AMF: CM-IDLE;and CM-CONNECTED

A UE in CM-CONNECTED state has a NAS signalling connection with the AMFover the N1 reference point. When a UE is in e.g. CM-CONNECTED state, itcan also be in RRC Inactive state. When in RRC Inactive state, at leastone of the following applies: the UE reachability is managed by the RAN,with assistance information from the core network, and/or the UE pagingis managed by the RAN, and/or the UE monitors for paging with the UE'sCN (5G S-TMSI) and the RAN identifier.

3GPP TS 23.501 V1.4.0 (2017-09) discloses the following in sections5.3.3.2.5, 5.4.2 and 5.4.6 regarding CM-CONNECTED with RRC Inactivestate, UE reachability in CM-CONNECTED and Core Network assisted RANparameters tuning:

CM-CONNECTED with RRC Inactive State

The RRC Inactive state applies to Next Generation-RAN (NG-RAN) (i.e. itapplies to New Radio (NR) and E-UTRA connected to 5G CN).

The AMF, based on network configuration may provide assistanceinformation to the NG RAN, to assist the NG RAN's decision whether theUE can be sent to RRC Inactive state.

The UE may provide indication of support for RRC inactive state on NASor AS layer.

The “RRC Inactive assistance information” comprises at least one of thefollowing information: UE specific DRX values, and/or the RegistrationArea provided to the UE, and/or Periodic Registration Update timer,and/or if the AMF has enabled MICO mode for the UE, an indication thatthe UE is in MICO mode.

The RRC Inactive assistance information mentioned above is provided bythe AMF during N2 activation with the (new) serving NG RAN node (i.e.during Registration, service request, handover) to assist the NG RAN'sdecision whether the UE can be sent to RRC Inactive state. RRC Inactiveis part of a RRC state machine, and it is up to the RAN to determine theconditions to enter RRC Inactive state. If any of the parametersincluded in the RRC Inactive Assistance Information changes as theresult of NAS procedure, the AMF shall update the RRC InactiveAssistance Information to the NG RAN node.

When the UE is in CM-CONNECTED state, if the AMF has provided RRCInactive assistance information, the RAN node may decide to move a UE toCM-CONNECTED with RRC Inactive state.

The state of the N2 and N3 reference points are not changed by the UEentering CM-CONNECTED with RRC Inactive state. A UE in RRC inactivestate is aware of the RAN Notification area.

With the introduction of RRC inactive state, the UE reachabilitymanagement is also moved down to RAN side in this state.

UE Reachability in CM-CONNECTED

For a UE in CM-CONNECTED state: the AMF knows the UE location on aserving (R)AN node granularity, and/or the NG-RAN notifies the AMF whenUE becomes unreachable from a RAN point of view.

UE RAN reachability management is used by the RAN for UEs in RRCInactive state. The location of a UE in RRC Inactive state is known bythe RAN on a RAN Notification area granularity. A UE in RRC Inactivestate is paged in cells of the RAN Notification area that is assigned tothe UEs. The RAN Notification area can be a subset of cells configuredin UE's Registration Area or all cells configured in the UE'sRegistration Area. The UE in RRC Inactive state performs Paging AreaUpdate when entering a cell that is not part of the RAN Notificationarea that is assigned to the UE.

At transition into RRC Inactive state, the RAN configures the UE with aperiodic RAN Notification Area Update timer value and the timer isrestarted in the UE and in the RAN with this initial timer value. Afterthe expiry of the periodic RAN Notification Area Update timer in the UE,the UE in RRC Inactive state performs periodic RAN Notification AreaUpdate.

To aid the UE reachability management in the AMF, upon the expiry of theperiodic RAN Notification Area Update timer in RAN, the RAN shall startan RRC release timer. If the RRC release timer expires, the RAN shallinitiate the UE context release in the AN procedure.

The current 3GPP TS 23.501 V1.4.0 (2017-09) also indicated that someparameters may be provided by the 5GC to the RAN (see text below).However, this currently defined information (i.e. expected UE activitybehaviour and expected HO behaviour) is not really related to the RANpaging.

Core Network Assisted RAN Parameters Tuning

The Core Network assisted RAN parameters tuning aids the RAN to minimizethe UE state transitions and achieve optimum network behaviour. How theRAN uses the CN assistance information is not defined.

The CN assistance information may be derived by the AMF per UE in theAMF based on collection of UE behaviour statistics and/or otheravailable information about the expected UE behaviour (such assubscribed DNN, SUPI ranges, or other information). If the communicationpattern parameters of the UE are available, the AMF may use thisinformation for selecting the CN assisted RAN parameter values. If theAMF is able to derive the Mobility Pattern of the UE, the AMF may takethe Mobility Pattern information into account when selecting the CNassisted RAN parameter values.

The communication pattern parameters and the Mobility Patterninformation are used by the AMF as input to derive the CN-assisted RANparameter values. The communication pattern parameters can beprovisioned by external party via the NEF. For the case ofstatistics-based CN assistance information collection, this may beenabled based on local configuration (e.g. subscribed DNN, SUPI rangesor other subscription information).

The CN assistance information provides the RAN with a way to understandthe UE behaviour for these aspects: “Expected UE activity behaviour”,i.e. the expected pattern of the UE's changes between CM-CONNECTED andCM-IDLE states (this may be derived e.g. from the statisticalinformation, or mobility pattern or from subscription information);“Expected HO behaviour”, i.e. the expected interval between inter-RANhandovers (this may be derived by the AMF e.g. from statisticalinformation, or the Mobility Pattern information of the UE or thesubscription information).

The AMF decides when to send this information to the RAN as “Expected UEbehaviour” carried in N2 signalling over the N2 interface.

The calculation of the CN assistance information, i.e. the algorithmsused and related criteria, and the decision when it is consideredsuitable and stable to send to the RAN may be vendor specific.

SUMMARY

An objective of embodiments herein is therefore to obviate at least oneof the above disadvantages and to provide improved paging.

According to a first aspect, the object is achieved by method performedby Control Plane, CP, node for handling paging. The CP node triggersthat a User Equipment, UE, should be paged by the Access Network, AN,node. The CP node transmits, when triggered, paging assistanceinformation to the AN node.

According to a second aspect, the object is achieved by a methodperformed by an AN node for handling paging. The AN node receives pagingassistance information from a CP node. The AN node determines a pagingstrategy based on the received paging assistance information. The ANnode pages the UE using the determined paging strategy.

According to a third aspect, the object is achieved by a CP node forhandling paging. The CP node is adapted to trigger that a UE should bepaged by an AN node, and to transmit, when triggered, paging assistanceinformation to the AN node.

According to a fourth aspect, the object is achieved by an AN node forhandling paging. The AN node is adapted to receive paging assistanceinformation from a CP node. The AN node is adapted to determine a pagingstrategy based on the received paging assistance information, and topage the UE using the determined paging strategy.

Thanks to the paging assistance information, the AN node has detailedand relevant information in order to be able to determine the pagingstrategy, i.e. the paging is improved.

Embodiments herein afford many advantages, of which a non-exhaustivelist of examples follows:

One advantage of the embodiments herein is that an optimized pagingstrategy can be formulated by Radio Access Network, RAN, based on itslocal info and information provided by 5GC in different procedures.

The embodiments herein are not limited to the features and advantagesmentioned above. A person skilled in the art will recognize additionalfeatures and advantages upon reading the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein will now be further described in more detail inthe following detailed description by reference to the appended drawingsillustrating the embodiments and in which:

FIG. 1 is a schematic drawing illustrating an example embodiment of a 5Gsystem.

FIG. 2 is a schematic drawing illustrating an example embodiment of a 5Gsystem.

FIG. 3 is a schematic drawing illustrating an example embodiment of acommunication system.

FIG. 4 is a signaling diagram illustrating embodiments of a method.

FIG. 5 is a flow chart illustrating embodiments of a method performed bya CP node.

FIG. 6 is a flow chart illustrating embodiments of a method performed byan AN node.

FIG. 7 is a schematic drawing illustrating embodiments of a CP node.

FIG. 8 is a schematic drawing illustrating embodiments of an AN node.

The drawings are not necessarily to scale and the dimensions of certainfeatures may have been exaggerated for the sake of clarity. Emphasis isinstead placed upon illustrating the principle of the embodimentsherein.

DETAILED DESCRIPTION

FIG. 3 is a schematic block diagram illustrating embodiments of a systemin which the embodiments herein may be implemented. The system may insome embodiments apply to one or more radio access technologies such asfor example Long Term Evolution (LTE), LTE Advanced, Wideband CodeDivision Multiple Access (WCDMA), Global System for MobileCommunications (GSM), 5G or any other Third Generation PartnershipProject (3GPP) radio access technology, or other radio accesstechnologies such as e.g. WLAN.

FIG. 3 illustrates a User Equipment, UE, 101 which is adapted tocommunicate with an Access Network (AN) node 103. The AN node 103 isadapted to communicate with a Control Plane, CP, node 105.

The UE 101 may be a device by which a subscriber may access servicesoffered by an operator's network and services outside operator's networkto which the operator's radio access network and core network provideaccess, e.g. access to the Internet. The UE 101 may be any device,mobile or stationary, enabled to communicate in the communicationsnetwork, for instance but not limited to e.g. user equipment, mobilephone, smart phone, sensors, meters, vehicles, household appliances,medical appliances, media players, cameras, Machine to Machine (M2M)device, Device to Device (D2D) device, Internet of Things (IoT) deviceor any type of consumer electronic, for instance but not limited totelevision, radio, lighting arrangements, tablet computer, laptop orPersonal Computer (PC). The UE 101 may be portable, pocket storable,hand held, computer comprised, or vehicle mounted devices, enabled tocommunicate voice and/or data, via the radio access network, withanother entity, such as another device or a server.

The AN node 103 may be referred to as a (R)AN node, a RAN node, a basestation, a NodeB, an eNodeB (eNB), a gNB, a RNC etc.

The CP node 105 may also be referred to as a CP function, a CP entity, anode implementing a CP function or any other suitable term for a unit ina control plane. The CP node 105 may be for example a 5G CP node. The CPnode 105 may be an Access and Mobility Management Function, AMF or aRadio AMF (RAMF).

The communication system exemplified in FIG. 3 may comprise otherentities than the ones illustrated, but the UE 101, the AN node 103 andthe CP node 105 are only illustrated for the sake of simplicity. Forexample, the communications system may comprise at least one of theentities illustrated in FIGS. 1 and 2 .

For the UE in RRC inactive state, RAN paging may be triggered in atleast one of the following cases: a) In case of downlink signaling,and/or b) In case of downlink data.

When the RAN paging (i.e. paging of the UE) is executed, a certainpaging strategy will be defined by the RAN. However, the RAN does nothave all the information related to the UE (e.g. Critical level of theMT signaling) or information related to the PDU session (e.g. DNN, thecritical level of the service) when applying the paging strategy in bothcases above. The current 3GPP standard has not addressed the issue yet.

According to the embodiments herein both static and dynamic pagingassistance information is provided to the RAN in different procedureseither at UE level or at PDU session level. At least part of the pagingassistance information can be used by the RAN as input parameters whenformulating a paging strategy when case a) and case b) happens for a UEin RRC in inactive state.

Static paging assistance information is static information when the UEcontext or the PDU session is established towards the RAN. It is validfor the live time of the UE context or the PDU session. Dynamic pagingassistance information is formulated when the AMF indicates the criticallevel of the current activity, which shall only be used by the RAN forthe current paging activity. The AMF formulates this information basedon the input when the MT event happens (e.g. some priority informationfrom other Network Functions (NF)).

Assistance information, also referred to as paging assistanceinformation, paging information or inactive assistance information(these terms are used interchangeably herein) is transmitted from the5GC to the RAN for a UE in RRC inactive state. The information isassistance information in the sense that it assists the AN node indetermining the paging strategy. The paging assistance information maycomprise at least one of the following parameters: Service priorityinformation and/or paging priority information. The service priorityinformation may comprise at least one of the following parameters:Priority level (1-256, generated by the CP node (e.g. the AMF) based ondifferent input), and/or Attributes (dynamic (i.e. one time usage) vs.static), and/or UE or PDU session level indication.

The paging priority information may correspond to the idle mode pagingpriority which much related to MPS priority service.

The paging assistance information may be provided from the AMF to theRAN in at least one of the following procedures: PDU sessionestablishment/modification, and/or Downlink NAS transport, and/or N2 UEcontext establishment/modification, and/or HO preparation, and/or

FIG. 4 is a signaling diagram illustrating embodiments of a method, withreference to the system in FIG. 3 . The figure illustrates for examplean embodiment of a paging assistance information delivery. The methodillustrated in FIG. 4 comprises at least one of the following steps,which steps may be performed in any suitable order than described below:

Step 401

The CP node 105 triggers a message to be transmitted to the AN node 103.The message may be a N2 message. An N2 message is a message to betransmitted over a N2 reference point. The N2 reference point may bebetween the CP node 105 and the AN node 103. The message may compriseinformation indicating modification of a PDU session resource. The UE101 is in RRC inactive state when this step is performed.

Step 402

The CP node 105 sends the triggered message to the AN node 103. Themessage may be a PDU session resource modification. The messagecomprises Paging assistance information. As mentioned above, the pagingassistance information may comprise at least one of the followingparameters: Service priority information and/or paging priorityinformation. The service priority information comprises at least one ofthe following parameters:Priority level (1-256, generated by AMF basedon different input), and/or Attributes (dynamic (i.e. one time usage)vs. static), and/or UE or PDU session level indication.

The paging priority information may correspond to the idle mode pagingpriority which much related to MPS priority service.

The AN node 103 receives the message from the CP node 105.

Step 403

The AN node 103 formulates a paging strategy for paging the UE 101.

Step 404

The AN node 103 pages the UE 101 according to the strategy in step 403.In addition, a RRC resume procedure may also be initiated.

The method described above will now be described seen from theperspective of CP node 105. FIG. 5 is a flowchart describing the presentmethod performed by the CP node 105, for handing paging. The CP node 105may be a 5G CP node. The CP node 105 may be an AMF. The method in FIG. 5comprises at least one of the following steps to be performed by the CPnode 105, which steps may be performed in any other suitable order thandescribed below:

Step 501

This step corresponds to step 401 in FIG. 4 . The CP node 105 triggersthat a UE 101 should be paged by an AN node 103. The UE 101 may be inRRC inactive state. The UE 101 may be in CM-Connected state with RRCinactive state.

The AN paging may be triggered in case of at least one of: downlinksignaling and/or downlink data.

Step 502

This step corresponds to step 402 in FIG. 4 . The CP node 105 transmits,when triggered, paging assistance information to the AN node 103.

The paging assistance information may be transmitted to the AN node 103in a message associated with at least one of the following procedures:PDU session establishment/modification, and/or Downlink NAS transport,and/or N2 UE context establishment/modification, and/or HO preparation.

The paging assistance information may comprise at least one of servicepriority information and/or paging priority information.

Service priority information comprised in the paging assistanceinformation may comprise at least one of the following: Priority level(1-256, generated by the CP node (105), based on different input),and/or Attributes (dynamic (i.e. one time usage) vs static), and/or UEor PDU session level indication.

The paging assistance information may comprise at least one of: staticand/or dynamic paging assistance information.

The paging assistance information may be transmitted to the AN node 103at UE level or at PDU session level.

To perform the method steps shown in FIG. 5 for handling paging, the CPnode 105 may comprises an arrangement as shown in FIG. 6 . The CP nodemay be a 5G CP node. The CP node may be an AMF.

The CP node 105 is adapted to, e.g. by means of a triggering module 601,trigger that a UE should be paged by an AN node. The UE may be in RRCinactive state. The UE may be in CM-Connected state with RRC inactivestate. The triggering module 601 may be a processor 602 comprised in theCP node 105.

The AN paging may be triggered in case of at least one of: downlinksignaling and/or downlink data.

The CP node is adapted to, e.g. by means of a transmitting module 603,transmit, when triggered, paging assistance information to the AN node.

The paging assistance information may be transmitted to the AN node in amessage associated with at least one of the following procedures: PDUsession establishment/modification, and/or Downlink NAS transport,and/or N2 UE context establishment/modification, and/or HO preparation.

The paging assistance information may comprise at least one of servicepriority information and/or paging priority information.

The service priority information comprised in the paging assistanceinformation may comprise at least one of the following: Priority level(1-256, generated by the CP node (105), based on different input),and/or Attributes (dynamic (i.e. one time usage) vs static), and/or UEor PDU session level indication.

The paging assistance information may comprise at least one of: staticand/or dynamic paging assistance information.

The paging assistance information is transmitted to the AN node 103 atUE level or at PDU session level.

The CP node is adapted to, e.g. by means of a receiving module 605,receive information and messages from other entities in the system.

In some embodiments, the CP node comprises the processor 602 and amemory 610. The memory 610 comprises instructions executable by theprocessor 602.

The memory 610 comprises one or more memory units. The memory 610 isarranged to be used to store data, received data streams, signalling,data, priority information, paging assistance information, pagingstrategy, local information, threshold values, time periods,configurations, schedulings, and applications to perform the methodsherein when being executed in the CP node.

In some embodiments, a computer program may comprise instructions which,when executed on at least one processor, cause the at least oneprocessor to carry out the method steps in FIGS. 4 and 5 . A carrier maycomprise the computer program, and the carrier is one of an electronicsignal, optical signal, radio signal or computer readable storagemedium.

The method described above will now be described seen from theperspective of AN node 103. FIG. 7 is a flowchart describing the presentmethod performed by the AN node for handing paging. The method in FIG. 7comprises at least one of the following steps to be performed by the ANnode 103, which steps may be performed in any other suitable order thandescribed below:

Step 701

This step corresponds to step 402 in FIG. 4 . The AN node 103 receivespaging assistance information from a CP node.

Step 702

This step corresponds to step 403 in FIG. 4 . The AN node 103 determinesa paging strategy based on the received paging assistance information.The paging strategy may also be referred to as a paging method, a pagingprocedure, a paging routine etc.

A paging strategy relates to how the AN node executes the paging interms of: i) the scope of the paging area (e.g. from small area to a bigarea, or paging in big area immediately); ii) a paging timer (e.g.waiting for the RRC resume from UE as paging response); and iii) apaging repetition handling (how many repetitions before giving up).

Step 703

This step corresponds to step 404 in FIG. 4 . The AN node 103 pages theUE using the determined paging strategy.

To perform the method steps shown in FIG. 7 for handling paging, the ANnode 103 may comprises an arrangement as shown in FIG. 8 .

The AN node is adapted to, e.g. by means of a receiving module 801,receive paging assistance information from a CP node. 34. The pagingassistance information may be received by the AN node 103 in a messageassociated with at least one of the following procedures: PDU sessionestablishment/modification, and/or Downlink NAS transport, and/or N2 UEcontext establishment/modification, and/or HO preparation.

The paging assistance information may comprise at least one of servicepriority information and/or paging priority information. The servicepriority information comprised in the paging assistance information maycomprise at least one of the following: Priority level (1-256, generatedby the CP node (105), based on different input), and/or Attributes(dynamic (i.e. one time usage) vs static), and/or UE or PDU sessionlevel indication.

The paging assistance information may comprise at least one of: staticand/or dynamic paging assistance information. The paging assistanceinformation may be received by the AN node 103 at UE level or at PDUsession level.

The AN node is adapted to, e.g. by means of a determining module 803,determine a paging strategy based on the received paging assistanceinformation. The determining module 803 may be a processor 805 comprisedin the AN node 103. The paging strategy may be determined further basedon local information comprised in the AN node.

The AN node is adapted to, e.g. by means of a paging module 808, pagethe UE using the determined paging strategy. 35. The UE 101 may be inRRC inactive state. The UE 101 may be in CM-Connected state with RRCinactive state.

The AN node is adapted to, e.g. by means of a transmitting module 810,transmit messages and information to other nodes in the system such ase.g. the UE and/or the CP node 105.

In some embodiments, the AN node comprises the processor 801 and amemory 813. The memory 813 comprises instructions executable by theprocessor 801.

The memory 813 comprises one or more memory units. The memory 813 isarranged to be used to store data, received data streams, signalling,data, priority information, paging assistance information, pagingstrategy, local information, threshold values, time periods,configurations, schedulings, and applications to perform the methodsherein when being executed in the AN node.

In some embodiments, a computer program may comprise instructions which,when executed on at least one processor, cause the at least oneprocessor to carry out the method steps in FIGS. 4 and 7 . A carrier maycomprise the computer program, and the carrier is one of an electronicsignal, optical signal, radio signal or computer readable storagemedium.

The present mechanism for handling paging may be implemented through oneor more processors, such as a processor 602 in the CP node arrangementdepicted in FIG. 6 and a processor 805 in the AN node arrangementdepicted in FIG. 8 , together with computer program code for performingthe functions of the embodiments herein. The processor may be forexample a Digital Signal Processor (DSP), Application SpecificIntegrated Circuit (ASIC) processor, Field-programmable gate array(FPGA) processor or microprocessor. The program code mentioned above mayalso be provided as a computer program product, for instance in the formof a data carrier carrying computer program code for performing theembodiments herein when being loaded into at least one of the CP nodeand/or the AN node. One such carrier may be in the form of a CD ROMdisc. It is however feasible with other data carriers such as a memorystick. The computer program code can furthermore be provided as pureprogram code on a server and downloaded to at least one of the CP nodeand/or the AN node.

The embodiments herein relate to RRC Inactive State Paging Assistanceinformation delivery.

The embodiments herein are not limited to the above describedembodiments. Various alternatives, modifications and equivalents may beused. Therefore, the above embodiments should not be taken as limitingthe scope of the embodiments. A feature from one embodiment may becombined with one or more features of any other embodiment.

It should be emphasized that the term “comprises/comprising” when usedin this specification is taken to specify the presence of statedfeatures, integers, steps or components, but does not preclude thepresence or addition of one or more other features, integers, steps,components or groups thereof. It should also be noted that the words “a”or “an” preceding an element do not exclude the presence of a pluralityof such elements. The terms “consisting of” or “consisting essentiallyof” may be used instead of the term comprising.

The term “configured to” used herein may also be referred to as“arranged to”, “adapted to”, “capable of” or “operative to”.

It should also be emphasised that the steps of the methods may, withoutdeparting from the embodiments herein, be performed in another orderthan the order in which they appear.

Example Embodiments

-   -   1. A method performed by a Control plane, CP, node 105, for        handling paging, the method comprising: triggering 401 that a UE        101 should be paged by a AN node 103; and transmitting 402, when        triggered, paging assistance information to the AN node 103.    -   2. The method according to any of the preceding embodiments,        wherein the AN paging is triggered in case of at least one of:        downlink signaling and/or downlink data.    -   3. The method according to any of the preceding embodiments,        wherein the paging assistance information is transmitted to the        AN node 103 in a message associated with at least one of the        following procedures: PDU session establishment/modification,        and/or Downlink NAS transport, and/or N2 UE context        establishment/modification, and/or HO preparation.    -   4. The method according to any of the preceding embodiments,        wherein the UE 101 is in RRC inactive state.    -   5. The method according to any of the preceding embodiments,        wherein the UE 101 is in CM-Connected state with RRC inactive        state.    -   6. The method according to any of the preceding embodiments,        wherein the paging assistance information comprises at least one        of service priority information and/or paging priority        information.    -   7. The method according to any of the preceding embodiments,        wherein service priority information comprised in the paging        assistance information comprises at least one of the following:        Priority level (1-256, generated by the CP node 105, based on        different input), and/or Attributes (dynamic (i.e. one time        usage) vs static) , and/or UE or PDU session level indication.    -   8. The method according to any of the preceding embodiments,        wherein the paging assistance information comprises at least one        of: static and/or dynamic paging assistance information.    -   9. The method according to any of the preceding embodiments,        wherein the paging assistance information is transmitted to the        AN node 103 at UE level or at PDU session level.    -   10. The method according to any of the preceding embodiments,        wherein the CP node 105 is a 5G CP node.    -   11. The method according to any of the preceding embodiments,        wherein the CP node 105 is an AMF.    -   12. A method performed by an Access Network, AN, node 103 for        handling paging, the method comprising: receiving 402 paging        assistance information from a Control plane, CP, node 105;        determining 403 a paging strategy based on the received paging        assistance information; and paging 404 the UE 101 using the        determined paging strategy.    -   13. The method according to any of the preceding embodiments,        wherein the paging strategy is determined further based on local        information comprised in the AN node 103.    -   14. The method according to any of the preceding embodiments,        wherein the paging assistance information is received by the AN        node 103 in a message associated with at least one of the        following procedures: PDU session establishment/modification,        and/or Downlink NAS transport, and/or N2 UE context        establishment/modification, and/or HO preparation.    -   15. The method according to any of the preceding embodiments,        wherein the UE 101 is in RRC inactive state.    -   16. The method according to any of the preceding embodiments,        wherein the UE 101 is in CM-Connected state with RRC inactive        state.    -   17. The method according to any of the preceding embodiments,        wherein the paging assistance information comprises at least one        of service priority information and/or paging priority        information.    -   18. The method according to any of the preceding embodiments,        wherein service priority information comprised in the paging        assistance information comprises at least one of the following:        Priority level (1-256, generated by the CP node 105, based on        different input), and/or Attributes (dynamic (i.e. one time        usage) vs static) , and/or UE or PDU session level indication.    -   19. The method according to any of the preceding embodiments,        wherein the paging assistance information comprises at least one        of: static and/or dynamic paging assistance information.    -   20. The method according to any of the preceding embodiments,        wherein the paging assistance information is received by the AN        node 103 at UE level or at PDU session level.    -   21. A Control plane, CP, node 105, for handling paging, the CP        node (105 being adapted to: trigger that a UE 101 should be        paged by a AN node 103; and to transmit, when triggered, paging        assistance information to the AN node 103.    -   22. The CP node 105 according to any of the preceding        embodiments, wherein the AN paging is triggered in case of at        least one of: downlink signaling and/or downlink data.    -   23. The CP node 105 according to any of the preceding        embodiments, wherein the paging assistance information is        transmitted to the AN node 103 in a message associated with at        least one of the following procedures: PDU session        establishment/modification, and/or Downlink NAS transport,        and/or N2 UE context establishment/modification, and/or HO        preparation.

24. The CP node 105 according to any of the preceding embodiments,wherein the UE 101 is in RRC inactive state.

-   -   25. The CP node 105 according to any of the preceding        embodiments, wherein the UE 101 is in CM-Connected state with        RRC inactive state.    -   26. The CP node 105 according to any of the preceding        embodiments, wherein the paging assistance information comprises        at least one of service priority information and/or paging        priority information.    -   27. The CP node 105 according to any of the preceding        embodiments, wherein service priority information comprised in        the paging assistance information comprises at least one of the        following: Priority level (1-256, generated by the CP node 105,        based on different input), and/or Attributes (dynamic (i.e. one        time usage) vs static), and/or UE or PDU session level        indication.    -   28. The CP node 105 according to any of the preceding        embodiments, wherein the paging assistance information comprises        at least one of: static and/or dynamic paging assistance        information.    -   29. The CP node 105 according to any of the preceding        embodiments, wherein the paging assistance information is        transmitted to the AN node 103 at UE level or at PDU session        level.    -   30. The CP node 105 according to any of the preceding        embodiments, wherein the CP node 105 is a 5G CP node.    -   31. The CP node 105 according to any of the preceding        embodiments, wherein the CP node 105 is an AMF.    -   32. An AN node 103 for handling paging, the AN node 103 being        adapted to: receive paging assistance information from a Control        plane, CP, node 105; determine a paging strategy based on the        received paging assistance information; and to page the UE 101        using the determined paging strategy.    -   33. The AN node 103 according to any of the preceding        embodiments, wherein the paging strategy is determined further        based on local information comprised in the AN node 103.    -   34. The AN node 103 according to any of the preceding        embodiments, wherein the paging assistance information is        received by the AN node 103 in a message associated with at        least one of the following procedures: PDU session        establishment/modification, and/or Downlink NAS transport,        and/or N2 UE context establishment/modification, and/or HO        preparation.    -   35. The AN node 103 according to any of the preceding        embodiments, wherein the UE 101 is in RRC inactive state.    -   36. The AN node 103 according to any of the preceding        embodiments, wherein the UE 101 is in CM-Connected state with        RRC inactive state.    -   37. The AN node 103 according to any of the preceding        embodiments, wherein the paging assistance information comprises        at least one of service priority information and/or paging        priority information.    -   38. The AN node 103 according to any of the preceding        embodiments, wherein service priority information comprised in        the paging assistance information comprises at least one of the        following: Priority level (1-256, generated by the CP node 105,        based on different input), and/or Attributes (dynamic (i.e. one        time usage) vs static), and/or UE or PDU session level        indication.    -   39. The AN node 103 according to any of the preceding        embodiments, wherein the paging assistance information comprises        at least one of: static and/or dynamic paging assistance        information.    -   40. The AN node 103 according to any of the preceding        embodiments, wherein the paging assistance information is        received by the RAN 103 at UE level or at PDU session level.    -   41. A system comprising a CP node 105 according to any one of        embodiments 21-31 and an AN node 103 according to any one of        embodiments 32-40.    -   42. A method performed by a system for handling paging, the        method comprising: triggering 401, at a CP node 105, that a UE        101 should be paged by a AN node 103; transmitting 402, when        triggered, paging assistance information from the CP node 105 to        the AN node 103; receiving 402, at the AN node 103, paging        assistance information from a Control plane, CP, node 105;        determining 403, at the AN node 103, a paging strategy based on        the received paging assistance information; paging 404, at the        AN node 103, the UE 101 using the determined paging strategy;        and detecting 404, at the UE 101 the paging from the AN node        103.    -   42. A computer program comprising instructions which, when        executed on at least one processor, cause the at least one        processor to carry out the method according to any one of        embodiments 1-11.    -   43. A carrier comprising the computer program of embodiment 42,        wherein the carrier is one of an electronic signal, optical        signal, radio signal or computer readable storage medium.    -   44. A computer program comprising instructions which, when        executed on at least one processor, cause the at least one        processor to carry out the method according to any one of        embodiments 12-20.    -   45. A carrier comprising the computer program of embodiment 44,        wherein the carrier is one of an electronic signal, optical        signal, radio signal or computer readable storage medium.    -   46. A computer program comprising instructions which, when        executed on at least one processor, cause the at least one        processor to carry out the method according to any one of        embodiments 41.    -   47. A carrier comprising the computer program of embodiment 46,        wherein the carrier is one of an electronic signal, optical        signal, radio signal or computer readable storage medium.

1-26. (canceled)
 27. A method, the method comprising: a control plane(CP) node generating a message comprising paging assistance information;and the CP node transmitting the message comprising the pagingassistance information toward an access network (AN) node, wherein thepaging assistance information comprises paging priority information thatindicates an importance of downlink signalling for a user equipment(UE), and the message comprising the paging assistance information is aUE context modification message configured to cause the AN node tomodify an established UE context associated with the UE so that themodified UE context associated with the UE includes the paging priorityinformation.
 28. The method of claim 27, wherein the UE is in RadioResource Control inactive state.
 29. The method of claim 27, wherein theUE is in Connection Management Connected state with RRC inactive state.30. The method of claim 27, the message comprising the paging assistanceinformation further comprises a UE identifier for identifying the UE anda protocol data unit (PDU) session identifier.
 31. The method of claim27, wherein the CP node is an Access and Mobility Management Function.32. The method of claim 27, further comprising: the AN node receivingthe message transmitted by the CP node; the AN node determining a pagingstrategy based on the paging assistance information included in thereceived message; and the AN node paging the UE using the determinedpaging strategy.
 33. A computer program product comprising anon-transitory computer readable medium storing a computer programcomprising instructions which, when executed on at least one processor,cause the at least one processor to carry out the method of claim 27.34. A method performed by an access network (AN) node for handlingpaging, the method comprising: receiving a message transmitted by acontrol plane (CP) node, wherein the message comprises paging assistanceinformation, the paging assistance information comprises paging priorityinformation, and the message comprising the paging assistanceinformation is a user equipment (UE) context modification messageconfigured to cause the AN node to modify an established UE contextassociated with a UE so that the modified UE context associated with theUE includes the paging priority information.
 35. The method of claim 34,further comprising: determining a paging strategy based on the receivedpaging assistance information; and paging a User Equipment (UE) usingthe determined paging strategy, wherein the UE is in Radio ResourceControl inactive state, or the UE is in Connection Management Connectedstate with RRC inactive state.
 36. The method of claim 35, wherein thepaging strategy is determined further based on local informationcomprised in the AN node.
 37. A computer program product comprising anon-transitory computer readable medium storing a computer programcomprising instructions which, when executed on at least one processor,cause the at least one processor to carry out the method of claim 34.38. A control plane (CP) node the CP node comprising: memory; andprocessing circuitry coupled to the memory, wherein the CP node isconfigured to: generate a message comprising paging assistanceinformation comprising paging priority information that indicates animportance of downlink signalling for a user equipment (UE); andtransmit the message comprising the paging assistance information towardan access network (AN) node, wherein the message comprising the pagingassistance information is a UE context modification message configuredto cause the AN node to modify an established UE context associated withthe UE so that the modified UE context associated with the UE includesthe paging priority information.
 39. The CP node of claim 38, whereinthe paging priority information comprises a paging priority value. 40.The CP node of claim 38, wherein the UE is in Radio Resource Controlinactive state, or the UE is in Connection Management Connected statewith RRC inactive state.
 41. An access network (AN) node, the ANcomprising: memory; a receiver for receiving a user equipment (UE)context modification message transmitted by a control plane (CP) node,wherein the UE context modification message comprises paging assistanceinformation comprising paging priority information; and processingcircuitry coupled to the memory, wherein the AN node is configured to:modify an established UE context associated with a UE so that themodified UE context associated with the UE includes the paging priorityinformation.
 42. The AN node of claim 41, wherein the AN is configuredto: determine a paging strategy based on received paging assistanceinformation; and page the UE using the determined paging strategy.
 43. Amethod comprising: a control plane (CP) node generating a messagecomprising paging assistance information; and the CP node transmittingthe message comprising the paging assistance information toward anaccess network (AN) node, wherein the paging assistance informationcomprises paging priority information that indicates an importance ofdownlink signalling for a user equipment (UE), the message comprisingthe paging assistance information is a UE context modification messageconfigured to cause the AN node to modify an established UE contextassociated with the UE so that the modified UE context associated withthe UE includes the paging priority information, and the method furthercomprises: the AN node receiving the message transmitted by the CP node;the AN determining a paging strategy based on the paging assistanceinformation included in the received message; and the AN paging a UserEquipment (UE) using the determined paging strategy.
 44. A methodcomprising: a control plane (CP) node generating a message comprisingpaging assistance information comprising a service priority valueindicating an importance of downlink signalling; and the CP nodetransmitting the message comprising the paging assistance informationtoward an access network (AN) node, wherein the message is a UE contextrequest message for causing the AN node to modify an established UEcontext associated with the UE to include the service priority value.